Immunopathogenic events of herpetic keratitis are poorly understood. The rabbit has been extensively used as an experimental model for the study of ocular infections caused by herpes simplex virus type 1 (HSV-1). In acute herpetic keratitis, the relationship between ocular viral shedding and the humoral response requires more extensive investigation. For this study, immunochemical procedures will be developed to detect viral antigens and host humoral responses. Specifically, rabbits will be infected by the ocular route with HSV-1. Sera, eye secretions, and corneal epithelial cells with be serially obtained from infected and mock-infected controls during the next four months. Eye secretions will be assayed for infectious virions by plaque assay and for viral antigens by enzyme-linked immunorsorbant assay (ELISA). Eye secretions and sera collected from the rabbits will be analyzed for the specific content of neutralizing antibody and total anti-HSV immunoglobulin by ELISA. The class of the antibody to HSV-1 detected by ELISA will also be determined for each sample. Corneal epithelial cells will be assayed for HSV-1 antigen by a sensitive avidin-biotin-mediated immunoperoxdiase staining procedure. The results will be correlated and statistically interpreted. The individual components of the local and systemic humoral response to HSV-1 will be related to the shedding of infectious particals and viral antigens. Data will be evaluated for prognostic indicators when the correlations are complete. The findings may increase our understanding of the disease state during the acute ocular HSV-1 infection. After this pilot study, other work may address the immunopathogenic events during the latent state, including cell mediated immunity and perhaps eventual therapy.